(a) Technical Field of the Invention
The present invention is generally related to circuit breakers, and more particular to a circuit breaking system providing over-current protection for a power circuit of high or ultra-high voltage without additional electricity provision.
(b) Description of the Prior Art
Circuit breaker is a device having an over-current protection function, and is usually applied to a main switch or a branch switch of in-house wiring, or serving as a vital component for appliance protection. Its main purpose is for short-circuit protection and for preventing overloading. Motors for industrial apparatus also require circuit breakers as a protection means. These circuit breakers are usually applied to low voltage circuits below 600 volts.
Circuit breakers for high or ultra-high voltage usually involve an electronic automatic protection mechanism that, when an extra-large current or extra-high voltage is detected, power provision is immediately cut off, or an input current or voltage is directly limited, so as to prevent apparatus damage from the extra-large or extra-high current or voltage.
However, the above circuit breakers have the following drawbacks.
Firstly, most circuit breakers are applicable to low voltage circuits only, and their applicability is therefore limited.
Secondly, for those suitable for high or ultra-high voltage circuits, additional electricity provision is usually required so as to sustain the operation of the electronic automatic protection mechanism.
Thirdly, disaster or accident sometimes would disrupt the additional electricity provision and as such the circuit breaker fails to complete the circuit breaking operation, thereby burning down the circuit breaker itself and downstream equipment.